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Jan. 3, 1928. 1,655,041

E. F. w. ALEXANDERSON REGULATING APPARATUS Filed Jan.15. 1926 2 Sheets-Sheet l \nverfcor H ss Afiborney Jan. 3, 1928.

E. F. W. ALEXANDERSON REGULATING APPARATUS Filed Jan. 15. 1926 2 Sheets-Sheet 2 Fig. 5.

Inventor Ernst F \A/. Aexanderson His Atbqrney.

and a small alternator 3t coupled to the alternator 1. With these connections the resultant voltage oipthe alternator 84 and the line. t is applied to the primary circuit of the tramst'ormcr 1 -3, and irrectitied potential of 'avalue which aries in' accordance with change in the niagnitudeof this resultant voltage is applied to the grid circuits of the device (3 through the transformer 20.

The potential applied to the gridslf is thus the resultant of component roltages one of which: is applied through the transforlmrr l8 and has its phase determined by the position of the phase shitter winding 2!- and the other of which is applied through the tl;\ll

former 20 and has its magnitude andphasc determined by the phase relation of the voltages otline t and. machine 314. The result. that should be produced by variation in these component voltages will be readilyiunderstood upon consideration of Fig.-2.

-.In Fig. 2 the internal and terminal voltages of the machine v1 when this machine is operated at a given load, is represented by the yectors E and E respectively, the volttransmission line isrepresented byih e rector li i 11f the, nachinedoad inc re ises, the internal and ite rminal-=voltages at the inachine are changed as indieatedby thefveetors E and vE respectia-ely; The po yeiyputput of the machine 1.is representedby {the product; (I-X +IX ).:(F.)', F; hein the perpendicular distance between tl egvector 1X and the origin This true ii or .r gisoii -tl iat the-sum of IX, and IX i idii'ectly pi-oportional to the machine curre A 11d theline rF iis directly proportional to ie ter ninal .voltage nultipliedby the poweritfaetor,

Stability in the operatiol i of the machine is maintained only w;l en' ai inc re ase in is immediately followed; by an 5 :incre- I n the product- IXg-t- IX ),itFl lfi the .opelation of: thergulatii gapparatus is ..sli iggish, this produet is not changed,promptly and the machine islik ol'yitolbeconie unstable and to fall out of step. the egulati ng ap paratus is sensitive andfwoigks' yei'yquickly, the .terminalvoltage yof tl e machin i I tained substantially Lcon stant d neyito the prompt increase. in excitation and internal voltage E oftheinachine. *IVith the-regulating apparatus showniby liig 1,themachine excitation and internal voltage E is auton'iatically regulated in accordance avith phasevariation ,of "the terniinalf v ol tage E In order ;to' 1 eadi-ly underistairdthe operation of this apparatus, a -vbri ef., considerationgot the operating characteristics o t;.tl i e .5ieeice,6 .Xlll hereqnired. Eli f ,Tl ie rnagi'i'itude of the current transmitted tothe alternator field winding throii'ghthe continuous arc device 6 is dependent on the relation between the rid and anode potentials of this device. 0 long as tli efgrid or anode potential is negative, no current is transmitted through thedevice. lVhen the grid and anode 'potentialsare both positive, current is t'ransu'iittied through the device. The exact point in each half cycle of anode wiltage at which the transmission of current through the device (3 is initiated determined by a change in the polarityof the grid potential from a negative to a positive value. This point may be rariedcitl'ier by changing the phase relation between the grid and anode potentials, or by eh angingjthe bias of an alternating potential applied to; the grids. -The current of the device .G is therefore zero-Whenits grid and anode potentials are 180 degrees out of phase, gradually in creasesas the phase of the gridvoltage is advanced with respect to that of theanode, andbecornes a maximum when the grid and anode voltage are brought into phase with one another; Variation-in a direet current bias voltage likewise has,theefi'ect of gr aduallyadvancing the point in the halfc-ycle at yvhich the transmission of curre11ttl1 ril0f,lh tirade-vi is i iat 1 Assuming the machines 3 and 34 to be driven ;byi-a suitable prime mover, the rotor justed 'to the proper 'positi on a nd the machine load to be constant, no potential isagppl d t th g id-i i u b-t meu t a -tan aio me fi ear ie nqugha n ea i sarrp d t r ugbith rl e 6-1 0 maintain. anima -v9la ;Ei.,= i s HQ i ..l. l3l w- ,lii-l 0 mea t me le d; n ase and the lea -hiv it ni it is put o 1 ,t 1 b e sl t-i9 -iti tit e it ieew ge at n rs-endow? ?e h ge,-.t,he esu t n Quest-sauna a ei pp edmth m-hea y nin n c .7 i vfiermea 20a hrmigh-ithe rect fi r ari s in r lueaaip si qh asp e a apn f flih g 1sirea t i 'e s at e tra sfw eini t h .i ein ,;atm ich a rt ifi ldiiv a rin s'; M92 .zcqmesiaial see-h.aia eyc -th nwde x l i i an the excitation of the jniachinei-ln isimmedi- ,ately increasedito a value that ensures stable .epe atien q :h m. 1h n ir i the ten:

ans-

in iteag eiin ei 13 Likew s if h l a i eiloada ee t a si phaseishifter 26 isiutilized for rough adjust- I mentsofthe machineexcitation and the matchine'voltage is re elated very sensitively.

lhe 'variabl'e' 'gr'i jbifls potential applied S thr ugh,the transformer 20. The variable .1 duced .by mzeans of a direct, current machine 35. -;'l li'e operation th is apparatus is 40', repregontdifierent values of, grid perm;

fjtialland't'he, per me er of batte ry 38 is represented a broliir line 38'. The phase relation between the anode and grid p6ten-' e sm nhe ,oad-=. ui p rat at normal 'volta'ge may be assumed to'be that indicated by curves 39 and &0. Under these conditions, the continuous arc device 6 opens at the instant t when the grid potential becomes positive and closes at the instant it, when the anode potential passes through its zero value, and the excitation of the field winding 2 is maintained at its normal value. If the voltage of the load circuit increases, the grid potential is increased, the device 6 opens at an instant of time subsequent to the time t, the current of the winding 2 is reduced and the load circuit voltage tends to decrease to its normal value. If the grid potential decreases to the value represented by the curve 40', the. grid is still positive at the instant 2 when the anode becomes positive and current is transmitted through the device 6 durim the entire half cycle, thus increasing the held excitation and restoring the load circuit voltageto its normal value without substantial delay between the beginning and correction of the variation from normal voltage.

The embodiments of the invention illustrated and described herein have been selected for the purpose of clearly setting forth the principles involved. It will be apparent, however, that the invention is susceptible of being modified to meet the different conditions encountered in its use and 65 I therefore aim to cgver by the appended bias, ,potentiali be; produced in various zreg'ulating apparatus i s replaced t souiceis'provide'df'for ap-' emboili ncnt. jillusclaims all modifications within the true spirit and scope of my invention.

'hat I claim as new and desire to secure h Letiers P' tent of the United States is:

I l. The combination of a circuit subject to unstableoperating conditions when its load crgceeds a predetermined value, means for icontrolling the-stability of said circuit, a continuous arc device comprising a' cathode and anode. connected to said control means v andagrid for controlling the transmission of current between said cathode andanode, and means operable in accordance with said conditions for applying to said grid a potential ivh'ereby accumulative changes in said conditions a re prevented.

}chii ie connprising exciting and armature. jwindifngs,excitation supply means compris- .ing'a vapor electric device provided with a cathode andan anodefconnccted to said excit ing winding and wit-h a grid for controlling the traiismission of currentbetwee-n said cathode and anode, and means operable in l ii inal voltage of said armature winding for regulating the potential applied to said grid.

v,i 'lhecombination of asynchronous ma- :chine provided with exciting and armature windings, direct current source, excitation ;.Isiipp' ly- Ineanscomprising a continuously ex- 'cited vapor electric device provided with a cathode and anode connectedto said excitation winding through'said source and with a grid arranged to prevent the starting of current between said cathode, and anode, and means operable to control the potential of said grid in response to variation in the terminal voltage of said armature winding.

4. The combination of an electrical machine provided with exciting and armature windings, excitation supply means comprising a vapor electric device provided with a cathode and an anode connected to said c.\'- citing winding and with a grid for controlling the transmission of current between said cat hode and anode. and means comprising an alternator driven in synchronism with said machine and connected to said armature winding in series relation between said'cathode and grid for regulating the potential of said grid in response to phase variation in the terminal voltage of said armature winding.

The combination of an electrical machine. provided with exciting and armature windings, excitation supply means comprising a vapor electric device provided with a cathode and an anode connected to said exciting winding and with a grid for controlling the transmission of current between said cathode and anode, means comprising an alternator driven in synchronism with said machine and connected to said armature winding in series relation between said cathresponse to change in the phase. of the, ter- '2. -'lhefcon1bination of an electrical maodo and grid for i egulnting the potential of said grid in response'to phase variation in l'lie to njnal voltage of said armature,- windling. the f naiism siw Q' i rr n between I I athqd land. ing fi,

ing, andvmeans for applying an alternating potgntial to said grid.

"Th0. combination of an electrical ma phine provided with jexcitl ng 1nd armaj t't lf )Ymding s, jQXClttltlOn supply Ing'ans com- ,p' ii sing 'a japor QlQCtIlC -d GVICQIJIOVldQd with -l0 g t x ig y ndi ng nnd;,w1 th a grl d for controlh sd. infl ti n: in

'i g tlie transmission.9f oni'ponQ between H .71; le pperatlng cond tions when 11s load exceeds chine;

stable 'conditio'n 'iwhen its loaidixsnidf rniaturo wind Zin .meaxis for 'av'nlving an altel natlnzz D0- ERNSTF. W. AIEEXANDERSON.

grid, and means for ad ust1ng 

